Coastal Areas Research Articles

Mining, characterization, and expression of a fructan sucrase for efficient conversion of soybean oligosaccharides

The high content of sucrose and raffinose reduces the prebiotic value of soybean oligosaccharides. Fructan sucrases can catalyze the conversion of sucrose and raffinose to high-value products such as fructooligosaccharides and melibiose. To obtain a fructan sucrase that can efficiently convert soybean oligosaccharides, we first mined the fructan sucrase gene from microorganisms in the coastal areas of Xisha Islands and Bohai Bay and then characterized the enzymatic and catalytic properties of the enzyme. Finally, recombinant extracellular expression of this gene was carried out in Bacillus subtilis. The results showed that a novel fructan sucrase, BhLS 39, was mined from Bacillus halotolerans. With sucrose and raffinose as substrates, BhLS 39 showed the optimal temperatures of 50 ℃ and 55 ℃, optimal pH 5.5 for both, and Kcat/Km ratio of 3.4 and 6.6 L/(mmol·s), respectively. When 400 g/L raffinose was used as the substrate, the melibiose conversion rate was 84.6% after 30 min treatment with 5 U BhLS 39. Furthermore, BhLS 39 catalyzed the conversion of sucrose to produce levan-type-fructooligosaccharide and levan. Then, the recombinant extracellular expression of BhLS 39 in B. subtilis was achieved. The co-expression of the intracellular chaperone DnaK and the extracellular chaperone PrsA increased the extracellular activity of the recombinant BhLS 39 by 5.2 folds to 17 U/mL compared with that of the control strain. BhLS 39 obtained in this study is conducive to improving the quality and economic benefits of soybean oligosaccharides. At the same time, the strategy used here to enhance the extracellular expression of BhLS 39 will also promote the efficient recombinant expression of other proteins in B. subtilis.

Analysis of the dynamic response of a model of an oyster farming structure

ABSTRACT Encouraged by the increase in oyster consumption, allied to the growth in the use of coastal marine areas, the development of oyster farming in open sea areas involves the joint efforts of different areas of knowledge. This interdisciplinarity is needed, given that the vibrations and hydrodynamics of structures can affect the distribution of food, the filtering capacity and hence the growth of these organisms. In this context, the article discusses the dynamic response of a hanging oyster farming structure subjected to the influence of different waves. The quantification of the relative velocity between the body and the fluid indicates that the oyster shells probably close part of the time. Lastly, by increasing the length of the cable supporting the cultivation line, an attenuation of approximately 60% can be achieved in the horizontal movement as a result of the distance from the system's natural frequency to that of excitation.

Significant Impact of a Daytime Halogen Oxidant on Coastal Air Quality.

Chlorine radicals (Cl·) are highly reactive and affect the fate of air pollutants. Several field studies in China have revealed elevated levels of daytime molecular chlorine (Cl2), which, upon photolysis, release substantial amounts of Cl· but are poorly represented in current chemical transport models. Here, we implemented a parametrization for the formation of daytime Cl2 through the photodissociation of particulate nitrate in acidic environments into a regional model and assessed its impact on coastal air quality during autumn in South China. The model could reproduce over 70% of the high Cl2 level measured at a coastal site, revealing a discernible presence of Cl2 and released Cl· in coastal and adjacent areas. Abundant Cl2 alters the oxidative capacity of the atmosphere, consequently increasing O3 (6-12%) and PM2.5 (10-16%) concentrations in high-NOx areas and reducing O3 (3%) concentration in low-NOx areas. Accounting for chlorine chemistry shifts the O3 - precursor relationships from VOC limited to mixed or NOx -limited regimes, enhancing the benefits of NOx emission reduction in mitigating O3 pollution. Our findings suggest that tightening emission control for two acidic pollutants, NOx and SO2, would alleviate reactive Cl· production and its adverse impact on air quality.

Impact of Long Well Screens on Monitoring of the Freshwater-Saltwater Transition Zone.

Deep monitoring wells with long screens crossing the transition zone between freshwater and saltwater are often used in coastal areas to characterize fresh groundwater resources and the depth of saline groundwater. However, past studies have demonstrated that long-screen wells can lead to biased observations of the transition zone, since vertical flow within the borehole can modify the shape and elevation of the transition zone in and around the borehole compared to undisturbed conditions without a well. Here, field observations and variable-density numerical flow simulations are used to evaluate, under natural flow conditions, how the installation of long-screen wells can provide time-varying biased observations of the freshwater-saltwater transition zone, and how various aquifer and well parameters affect the magnitude of these biases. Results show that long-screen wells can lead to a more dispersed interface, an upward displacement of the transition zone of between 5 and 10 m, and a salinity decrease in the saltwater portion of the well on the order of 10 to 15 g/L. The perturbations take up to 5 years to fully develop and stabilize. The degree of displacement depends on the screen diameter, screen length, aquifer anisotropy, and hydraulic conductivity, whereas the displacement is independent of the distance of the well from the coast. This analysis provides insight into which well and aquifer characteristics increase the risk of obtaining biased observations in long-screen wells, and provides orders of magnitude for these biases.

Modelling Impacts of Climate Change and Anthropogenic Activities on Ecosystem State Variables of Water Quality in the Cat Ba–Ha Long Coastal Area (Vietnam)

Modelling Impacts of Climate Change and Anthropogenic Activities on Ecosystem State Variables of Water Quality in the Cat Ba–Ha Long Coastal Area (Vietnam)

International pellet watch; origins and monitoring of oil markers in surface sediments and plastic resin pellets in southern Caspian Sea, Iran.

Oil pollution in marine environments, particularly along the southern coasts of the Caspian Sea, has become a serious issue due to anthropogenic activities such as shipping, tourism, fishing, and urban development. This study aimed to assess the concentration and origin of PAHs, n-alkanes, hopanes, and steranes in sediment samples (coastal area and coastal line) and resin pellets collected from 30 stations along the southern shores of the Caspian Sea (Golestan, Mazandaran, and Gilan provinces). The results showed that PAHs concentrationranged from 530.4 to 9201ng/g-dw in coastal area sediments, 753 to 10,528ng/g-dw in coastal line sediments, and 5920.7 to 16,548ng/g-pellet in resin pellets. The average total concentration of alkanes ranged from 251 to 7059μg/g-dw in coastal area sediments, 273 to 8401.6μg/g-dw in coastal line sediments, and 1967 to 22,258μg/g-pellet in resin pellets. The total terpene concentration in coastal area sediments was 60.5 to 537.5ng/g-dw, in coastal line sediments 120.6 to 811.3ng/g-dw, and in resin pellets 227 to 2886.5ng/g-pellet. Additionally, the highest concentrationwere observed in port-related areas (Bandar Anzali, Amirabad, and Astara), while the lowest concentrationwere found in recreational areas. Resin pellets generally exhibited higher concentrationof all investigated compounds compared to sediments. The classification of PAH pollution intensity based on global criteria indicated moderate to very high contamination in sediments and high to very high contamination in resin pellets. The determination of pollution levels based on the concentration of n-alkanes in southern Caspian Sea sediments revealed very high and considerable pollution. The categorization of hopane compounds' pollution intensity in resin pellets, according to International Pellet Watch classification, indicated a lack of pollution in all samples. The primary source of all compounds was identified as petrogenic.

National scale evaluation of nutrient purification capacity in marine sediments along the coast of South Korea: A mesocosm study based in situ assessment.

The ecosystem regulating services from tidal flats, such as removal of organic pollutants, provided by natural tidal flats are being increasingly recognized, yet quantitative evaluation remains limited. Here we evaluated a nationwide capacity of natural purification in tidal flats. Using in situ sediments from five along the Korean coast (Incheon, Gunsan, Sinan, Gwangyang, and Busan), we applied a mesocosm system informed by 18years of riverine monitoring data from national surveys. In particular, we adopted an integrated approach, analyzing nutrient fluxes, removal rates, and their economic value. The results indicated that in all regions, the water-sediment fluxes of all nutrients showed negative values, indicating the migration of nutrients from the overlying water to the sediment. A significant (p<0.01) difference among regions of water-sediment fluxes was primarily due to exposed nutrient concentrations. Notably, the presence of greater total nitrogen (TN) and total phosphorus (TP) purification capacities in Incheon and Nakdong sediments reflected in remaining loads of river-estuarine continuum. Nationwide, the nutrient purification capacities of Korean tidal flats (2491km2) were estimated at 0.29 Tg N yr-1 and 0.15 Tg P yr-1, equating to economic values of 8.26 billion USD yr-1 and 8.21 billion USD yr-1, respectively. Scaling globally, the economic values for TN and TP removal by tidal flats (124,921km2) reached 414 billion USD yr-1 and 412 billion USD yr-1. Overall, the integrated approach successfully provided the first national-scale evaluation of nutrient removal capacity in tidal flats across Korea, addressing the ecological and economic significance of tidal flats, while underscoring the need for their conservation and management strategies of coastal areas globally.

Transformasi Pesisir Jakarta: Kajian Komprehensif Giant Sea Wall untuk Keberlanjutan Sosial, Ekonomi, dan Ekologis

Jakarta faces a serious flood threat due to a combination of sea level rise, land subversion due to groundwater exploitation, and extreme rainfall. The Giant Sea Wall project is proposed as a solution to reduce annual economic losses of Rp 2.1 trillion, while protecting the city from flash floods and river floods, as well as supporting the development of coastal business and tourism areas. However, this project is faced with major challenges, such as funding needs that require innovation in the form of Green Financing and public-private partnerships, social resistance due to lack of community involvement, as well as ecological impacts such as the loss of mangrove habitat and disruption of sedimentation patterns. Global studies, such as Delta Works in the Netherlands, highlight the importance of ecosystem-based approaches and integrated design to ensure sustainability. The success of this project depends on the integration of mangrove restoration, the use of advanced technology, inclusive policies, and the active involvement of local communities to ensure equitable socio-economic impact as well as long-term sustainability.

Ecological risk assessment for BDE-47 in marine environment based on species sensitivity distribution method.

BDE-47 is the most abundant and toxic congener in the marine environment. Assessing the ecological risk of BDE-47 in seawater is of great importance to protect the marine species. However, the ecological risks of BDE-47 on marine species is still limited. In the present study, the hazardous concentrations for 5 % of species (HC5) values of BDE-47 were derived by species sensitivity distributions (SSD), the short-term water quality criteria (SWQC) and long-term water quality criteria (LWQC) were acquired from HC5. Moreover, the marine ecological risk of BDE-47 was assessed by the risk quotient (RQ) method in the coastal area of China. The SWQC and LWQC were 1.06μg/L and 0.61μg/L, respectively. According to published literature, the concentrations of BDE-47 ranged from undetected to 9.06ng/L, BDE-47 has no risk to marine species in most coastal areas, but might show low risk for a long exposure time in the coastal mariculture area of China. This study provides a new approach for the derivation of the WQC and the ecological risk assessment of BDE-47, which is essential for the protection of marine species and provides guidance to manage the concentration of BDE-47 for administrative department.

Construction of energy consumption monitoring system for energy saving equipment in seawater desalination based on whale algorithm

ABSTRACT Seawater desalination has emerged as a pivotal solution to address freshwater scarcity in coastal regions, with China being a prominent adopter of this technology. This paper compares three large-scale seawater desalination projects in China: the Six Heng Water Treatment Plant, the Caofeidian Desalination Project, and the Huaihai Yu Huan Power Plant Desalination Project. Each project employs distinct desalination technologies, including reverse osmosis and dual-membrane processes. We evaluate these systems’ operational parameters, performance indicators, and cost-effectiveness over their operational lifespans. Key considerations include seawater intake, pretreatment processes, reverse osmosis desalination, energy recovery systems, and post-treatment mineralisation. The analysis highlights these desalination plants’ efficiency, sustainability, and economic viability in addressing freshwater demands in their respective regions. Insights from this comparative study contribute to optimising seawater desalination processes, enhancing water resource management, and guiding future infrastructure development efforts in coastal areas.

Will Olive Groves have a Future Under Climate Change Conditions in The North Aegean Sub-Region, a Mediterranean Agricultural Ecosystem of Türkiye?

The study is aimed at investigating future changes in sustainability of olive farming by means of climate change, and changes in agricultural climatic suitableness and phenology of olive tree cultivation in the North Aegean sub-region of Türkiye mainly characterised with dry summer subtropical Mediterranean climate. According to projected changes based on RCP8.5 scenario, projected warming reaches an average of 5-6°C increase indicating most negative condition on olive cultivation. According to RCP8.5 scenario annual precipitation projections, present suitable areas of olive groves will decrease in the period of 2049-2073, and almost the entire study area will be in the category of medium suitable. With respect to projected Emberger Bioclimate classification, for RCP 8.5 scenario, there will be a significant increase in dry-sub humid areas in the period of 2049-2073. This increase will cover up the coastal areas in the period of 2074-2098, and even all the study region will be very likely characterised with dry-sub humid and semi-arid Mediterranean bioclimatic types except for some coastal areas. An increase of about 6°C is expected in maximum values of maximum air temperatures during the bud swelling periods in the spring, especially after 2050 under RCP8.5 scenario. This increase in extreme maximum temperatures may cause olive trees to bloom earlier and prolong the growth period. By regarding the high vernalization requirement of main olive variety in the study area, a 6°C temperature increase may significantly decrease olive yields and will force farmers to transition to new varieties with relatively low vernalization requirements. According to both RCP scenarios, there is a possibility of extension of suitable areas for olive cultivation towards low to mid-elevation plateaus and mid-elevation slopes of mountainous areas and high plateaus particularly facing suitable aspects to lower negative effects of projected future warming and dryness.

Comparative Performance of Sentinel-2 and Landsat-9 Data for Raw Materials’ Exploration Onshore and in Coastal Areas

The demand for Critical Raw Materials (CRM) is increasing due to the need to decarbonize economies and transition to a sustainable low-carbon future achieving climate goals. To address this, the European Union is investing in the discovery of new mineral deposits within its territory. The S34I project (Secure and Sustainable Supply of Raw Materials for EU Industry) is developing Earth observation (EO) methods to support this goal. This study compares the performance of two satellites, Sentinel-2 and Landsat-9, for mineral exploration in two geologically distinct areas in northern Spain. The first area, Ria de Vigo, contains marine placer deposits of heavy minerals, while the second, Aramo, hosts Co-Ni epithermal deposits. These sites provide exceptional case studies to improve EO-based methods for CRM exploration onshore and coastal regions, focusing on deposits often overlooked in remote sensing studies. Standard remote sensing methods such as RGB combinations, Principal Component Analysis (PCA), and band ratios were adapted and compared for both satellites. The results showed similar performance in the Ria de Vigo area, but Sentinel-2 performed better in Aramo, identifying a higher number of zones of mineral alterations. The study highlights the advantages of Sentinel-2’s higher spatial resolution, especially for mapping smaller or more scattered mineral deposits. These findings suggest that Sentinel-2 could play a larger role in mineral exploration. This research provides valuable insights into using EO data for diverse CRM deposits.

Wind–Wave Misalignment in Irish Waters and Its Impact on Floating Offshore Wind Turbines

This study examined the impact of wind–wave misalignment on floating offshore wind turbines (FOWTs) in Irish waters, analysing average weather and extreme events, including hurricane conditions. Using the ERA5 reanalysis dataset validated against Irish Marine Data Buoy Observation Network measurements, the results showed a satisfactory accuracy with an average wind speed error of −0.54 m/s and a strong correlation coefficient of 0.92. Wind–wave misalignment was found to be inversely correlated with wind speed (correlation coefficient: −0.41), with minimum misalignment occurring approximately seven hours after a change in wind direction. The study revealed that misalignment could exceed 30∘ during hurricanes, contradicting standard assumptions of alignment under extreme conditions. The investigation highlighted that in western coastal areas, average misalignment could reach 57.95∘, while sheltered Irish Sea regions experienced lower values, such as 23.06∘. Numerical simulations confirmed that these misalignment events amplified side-to-side turbine deflections significantly. This research underscores the need to incorporate misalignment effects into industry testing standards and suggests that current methodologies may underestimate fatigue loads by up to 50%. This work emphasizes improved design and testing protocols for FOWTs in complex marine environments and highlights the suitability of ERA5 for climate analysis in Ireland.

The Role of Applied Mathematics in Typhoon Hazard Assessment: From Statistical Models to Risk Prediction

Typhoons, as tropical cyclones occurring in the western Pacific, are one of the most destructive natural disasters, often causing severe impacts on coastal areas. With the gradual increase in typhoon intensity, predicting typhoon paths and their strengths is crucial to mitigate their threat to human lives and economic infrastructure. In recent years, the importance of applied mathematics, especially statistical modelling, in typhoon hazard assessment has become increasingly prominent. This paper discusses the application of statistical models such as extreme value theory, time series analysis and multiple regression analysis in typhoon risk prediction, aiming to reveal the key role of applied mathematics in typhoon disaster assessment, and to provide a theoretical basis for improving the accuracy of prediction and formulating effective response strategies. Through this study, it helps to improve the accuracy of typhoon track and intensity prediction, and provides scientific support for coping with the increasing typhoon disasters. In addition, this study provides an important theoretical basis and reference direction for relevant departments to formulate disaster prevention and mitigation strategies

Seed Dormancy and Germination Potential of Coastal Rice Landraces in Bangladesh: Implications for Climate-Resilient Cultivation

The coastal regions of Bangladesh host a rich diversity of Aman rice landraces, which are crucial for local agriculture but are highly vulnerable to natural disasters like cyclones and floods. Specifically, local landraces often experience flooding during grain filling and maturation stages, and sprouts in the field lead to a severe loss of yield. Seed dormancy, which delays germination, is a key trait for escaping sprouting in the field during harvesting. However, there is lack of information on genetic variability in the existing rice landraces grown in the coastal area of Bangladesh. This study evaluated the seed dormancy of 28 local Aman rice landraces, plus four varieties from the Bangladesh Institute of Nuclear Agriculture and Bangladesh Rice Research Institute. Germination tests were conducted under controlled conditions, and an electrical conductivity (EC) test was used to assess seed vigor. The results showed that Bari Mota, Tulsimala, Chinigura, Dishari, and Birindi exhibited the highest dormancy rates, i.e., 100%, 100%, 99%, 99%, and 99%, respectively, while BINA Dhan 10, Nona Bokra, and BINA Dhan 8 had the lowest dormancy rates, with values of 11%, 16%, and 24%, respectively. Priming treatments enhanced germination rates in some varieties; however, others, such as Bari Mota and Tulsimala, remained dormant, underscoring the variability in seed dormancy levels. Compared to non-priming, a significant improvement of germination was recorded in BRRI dhan 41 (85.3% vs. 9%), Motha mota (84% vs. 8%), Lal chikon (74.6% vs. 1%), Sadamota (74.6% vs. 5%), and Bashful (53.3% vs. 3%). Altogether, our results suggest that local landraces are diverse in seed dormancy, and genotypes with high dormancy, such as Bari Mota and Tulsimala, can potentially be grown in the disaster-prone coastal areas. In contrast, these genotypes can be used for future breeding programs. Therefore, this study carries significant implications for rice cultivation in the coastal areas of Bangladesh.

Understanding the spread of agriculture in the Western Mediterranean (6th-3rd millennia BC) with Machine Learning tools

The first Neolithic farmers arrived in the Western Mediterranean area from the East. They established settlements in coastal areas and over time migrated to new environments, adapting to changing ecological and climatic conditions. While farming practices and settlements in the Western Mediterranean differ greatly from those known in the Eastern Mediterranean and central Europe, the extent to which these differences are connected to the local environment and climate is unclear. Here, we tackle this question by compiling data and proxies at a superregional and multi-scale level, including archaeobotanical information, radiocarbon dates and paleoclimatic models, then applying a machine learning approach to investigate the impact of ecological and climatic constraints on the first Neolithic humans and crops. This approach facilitates calculating the pace of spread of farming in the Western Mediterranean area, modelling and estimating the potential areas suitable for settlement location, and discriminating distinct types of crop cultivation under changing climatic conditions that characterized the period 5900 – 2300 cal. BC. The results of this study shed light onto the past climate variability and its influence on human distribution in the Western Mediterranean area, but also discriminate sensitive parameters for successful agricultural practices.

Soil quality indicator-based land productivity modelling for agricultural sustainability.

Rapid population expansion has made food security a global concern for humanity, necessitating a sustainable assessment of natural resources. Well evaluated and managed soil is one of the most significant resources that can assist close the gap between supply and demand for food to attain food security. A precise assessment of land productivity (LP) is essential for sustainable land use management. The primary aim of this research is to predict the land productivity index (LPI) for certain locations on Egypt's northwest coast under current conditions using soil quality indicators (SQIs). Additionally, the study proposed relevant management actions to boost land productivity in the future. To achieve this aim, a spatial model was created to assess LPI for some areas in the north western coast of Egypt. LP equation was used to estimate current land productivity index (CLPI) and potential land productivity index (PLPI). Results found that the study area mainly located under two classes of CLPI, e.g., average (class ⅡⅠ) represents an area of 13322.63 ha (67.55%) and good grade (class Ⅱ) covers an area of 4339.78 ha (22%). PLPI grades were good (II) and average (III) with an area of 16192.54 ha (82.10%) and 1903.23 ha (9.65%), respectively. The finding showed that more than 60% of the studied area was converted from poor and average class to good class after applying the proposed solutions of soil improvement. The methodology presented here can easily be replicated under similar circumstances in arid zones, allowing local governments and decision-makers to utilize the quantitative results obtained to ensure sustainable development.

Ecological insights on the feeding behaviour of waterbirds in an Important Bird and Biodiversity Area of South West Johor Coast, Malaysia.

Mangroves and mudflats are essential intertidal habitats that support benthic communities, providing critical feeding grounds for waterbirds. However, the degradation of these habitats due to coastal reclamation poses significant threats to prey availability and waterbird populations along the South est Johor Coast. While most avian research in Johor focuses on forest birds, studies on coastal waterbirds, particularly their feeding ecology, remain scarce. Understanding the feeding ecology of waterbirds is crucial for strengthening conservation efforts in vulnerable intertidal habitats. This study investigated the feeding behaviour and diet composition of waterbirds along the South West Johor Coast, Malaysia. Fieldwork was conducted in three coastal mudflats from November 2020 to May 2021, employing the direct observation technique. A total of 576 hours of observation were recorded, averaging 2 hours and 19 minutes per focal observation. Of 17 waterbird species recorded, only 11 species were included in the analysis based on sufficient data. The results revealed that waterbirds primarily consumed fish, molluscs, worms, crabs and unidentified prey, with fish comprising 25% of their overall diet. Feeding behaviour varied significantly by morphology traits, with larger waterbirds demonstrating higher feeding efficiency. Despite lower feeding rates and shorter feeding durations, larger species had a greater percentage of successful feeding attempts, indicating their superior ability to meet energy requirements. These findings provide crucial baseline data for understanding waterbird feeding ecology and highlight the importance of conserving the intertidal habitats. This research contributes to the development of targeted conservation strategies for waterbirds in the Important Bird and Biodiversity Area (IBA) of the South West Johor Coast, Malaysia, an area increasingly at risk from habitat degradation.

Modelling Population and Health Profiles in Italian and European Coastal and non-Coastal Areas

Modelling Population and Health Profiles in Italian and European Coastal and non-Coastal Areas

Identification of Characteristics, Abundance, Color, and Size of Microplastics in Shellfish in the Coastal Waters of Galesong Beach

The increasing presence of microplastics in the waters has been known to have the potential to enter various types of marine biota including shellfish. the type of research conducted was descriptive observational research) The research location was the coastal area of North Galesong Beach, Takalar Regency. The results showed that the average abundance of microplastics in mussels in Galesong Waters was 4,258 items/individual. The average (mean) intake rate of respondents was 185.86 gr/day, the median value was 167 gr/day. The minimum intake rate was 115 gr/day and the maximum intake rate was 300 gr/day. The mean exposure frequency of respondents was 126 days, the median was 104 days. The minimum exposure frequency was 54 days and the maximum exposure frequency was 255 gr/day. the types of microplastics found were all in the form of lines, fragments with red, blue and black colors. The size found was between 0.505-10.488 mm. The most common type of microplastics found in both sediments and mussels is the fragment form, followed by lines with a variety of colors, namely red, blue and black, there are differences in microplastics abundance between the two types of mussels, but differences in abundance can be seen between research stations as mussel habitat.